Wall brush



FIG. 1 is a perspective view of a wall brush showing our new design;

FIG. 2 is a reduced front elevation view thereof;

FIG. 3 is an enlarged left side elevation view thereof;

FIG. 4 is a right side elevation view of the design as shown in FIG. 3;

FIG. 5 is a top plan view of the design as shown in FIG. 2; and,

FIG. 6 is a bottom plan view of the design as shown in FIG. 2.

The broken lines are included to illustrate portions of the wall brush that form no part of the claimed design. 

The ornamental design for a wall brush, as shown and described. 